With Sen. Herman E. Talmadge insisting right to the end that he was guilty only of mistakes but no intention wrongs, the Senate Select Committee on Ethics concluded its 13-month investigation yesterday into allegation against the powerful Georgia Democrat.

"I am human and I've made errors," Talmadge said in a closing statement to the six-member panel. But, he added, "To the best of my ability I have never used my office for profit. I never have and I never will."

The committee must now recommend to the Senate whether disciplinary action should be taken against Talmadge. Such a recommendation for punitive action could range from a simple reprimand to expulsion. But under Senate rules any recommendation against Talmadge, a 23-year Senate veteran, would require at least a 4-to-2 vote of the ethics panel.

Talmadge has been accused by the committee's special counsel, Carl Eardley, of five separate charges of financial misconduct. The most serious of the charges allege that he filed false expense accounts for more than $50,000 with the Senate and diverted campaign contributions to his own use through a secret bank account.

Ethics Committee officials said yesterday that it likely will be several weeks before the panel's formal recommendation on the case is sent to the Senate.

In his closing statement, committee Chairman Adlai E. Stevenson (D-Ill.) sharply criticized Talmadge for a lack of contrition during two days of testimony this week on the charges.

"Why, throughout your testimony," asked Stevenson, "have you expressed no regret, no contrition for the embarrassment you have caused the Senate, for the burdens you have occasioned on your peers, for the expense you have occasioned to the taxpayers for this whole story episode?"

"I do regret this happened," Talmadge answered.

Talmadge aides later said the Georgia senator has also expressed "deep regret" during an executive session with the committee last year. But speaking to reporters yesterday, Talmadge said that "I've done nothing that warrants any disciplinary action by the Senate."

"I paid back $37,125," he said. "If that's not contrition, I don't know what is."

Talmadge was referring to a reimbursement he made to the Senate last year after an audit of his office records showed some $50,000 in false expense vouchers filed from 1971 to 1977.

Talmadge has refused to pay the rest to the Senate because he said it was embezzled by his former chief aide, Daniel Minchew, Minchew was the committee's chief witness against Talmadge during the hearings.

While he defended the rest of his past and present staff for what he said were "honest mistakes" in filing the false expense accounts, Talmadge said his worst mistake was hiring Minchew in 1971.

"It was the most serious mistake I've ever made in my 30-year political career," he said.

During his testimony, Talmadge parried with committee counsel Doughlas McCullough over several bank accounts the senator maintained for office and personal funds. Talmadge said he could not recall the details of transfers from one account to another after McCullough suggested he had used office money to supplement his personal finances.

Pulling several coins from his pocket, Talmadge jingled them from hand to hand to explain the transfers. "It was all my money," he said of the funds that ended up in his personal bank account.

Talmadge was pressed by committee Vice Chairman Harrison H. Schmitt (R-N.M.) about his contention that neither he nor anyone in his office noticed the alleged embezzlement by Minchew of thousands of dollars in improper Senate reimbursements.

"The funds coming back from the Senate I thought were my funds," said Talmadge. "Why would I enter into any sort of foolish and ridiculous scheme with an administrative assistant?"

He noted that Minchew had set up a secret bank account in Talmadge's name to launder the Senate payments and other campaign contributions.

"To enter into a conspiracy to steal that by setting up a bank account is the height of folly," Talmadge said.

Talmadge said he believed Minchew stole some $16,000 from the secret account that auditors have been unable to trace.

But he conceded that even after Minchew told him last June 14 that some of the office expense money had been diverted to the senator - a claim Talmadge has called a blackmail attempt - he allowed Minchew to sit in on an office strategy session the same day about the expense money.

"I find it difficult to understand why he attended that meeting," Schmitt said.

Talmadge said that despite the alleged blackmail attempt hours before, he allowed his former aide to stay because "I had more important things on my mind than Mr. Minchew." CAPTION: Picture, Taimadge, right, with attorney James Hamilton, at Senate hearing: "I am human and I've made errors." AP