The Navy is investigating an Oakland, Calif., naval hospital where two former Navy men have died and a third ended up in critical condition after problems developed during routine operations.

The investigation, announced last week, will center on charges initiated by a resident doctor that there is a "critical lack" of equipment and staff in the anesthesiology department at the Naval Regional Medical Center in Oakland. It will be headed by Rear Adm. Stanley J. Anderson, the Navy's inspector general.

The three cases that have come to light occurred between June 24 and July 15.

In the first, 79-year-old Joachim Minor, a retired machinist's mate from Dublin, Calif., had a routine gall bladder operation June 24. Several hours later, in what one doctor described as "clearly the result of negligence and abandonment." Minor was found unattended in a hospital room in critical condition.He died soon after.

Two days later, on June 26, Clifford E. Christian, 63, a retired aviator's machinist's mate from Oakland, died at the hospital. Christian had entered the hospital the previous week complaining of swollen ankles and legs. During an operation, the tip of a syringe needle allegedly broke off in his chest, leading to a collapsed lung, brain damage and a fatal heart attack.

In the third case, 49-year-old Gene Raymond of Modesto, a retired supply man, suffered a heart attack before wrist surgery on july 15. Irregularities in the anesthesiology department led to the heart attack, it is alleged. Raymond is now in critical condition at nearby Stanford University Medical Hospital.

The three cases are described in a July 26 letter to Secretary of the Navy W. Graham Claytor from Reps. Thomas J. Downey (D-N.Y.), Ronald V. Dellus (D-Calif.) and Fortney Stark (D-Calif.). The three asked Claytor to begin a full-scale investigation of the incidents.

The Naval Regional Medical Center in Oakland is a highly regarded facility where present and former members of the uniformed services received free medical treatment.

The hospital has 413 beds, 103 staff and faculty members, 111 residents and 40 interns, a spokesman said. Last year, it treated 14,175 in-patients and 351,800 out-patients.

It is one of only a handful of teaching hospitals in the Navy, the spokesman said. In recent years, he said, none of the residents trained at the hospital has failed to pass the board examinations that qualify physicians for specialty work.

The medical center, however, suffers from a serious problem common to all military hospitals. With the end of the draft, military hospitals are finding it increasingly difficult to attract and retain the number of physicians needed to provide top-quality health care.

The problem is becoming expecially acute this summer, as a large number of doctors who entered the services during the Vietnam war are ending their tours. For the Navy, the shortage was about 200 doctors last month. The Armed was short 370 doctors at the time, and the Air Force 389.

The doctor shortage is cited in Minor's case by Dr. David L. Crane, a resident at the medical center whose complaints and letters provided the impetus for the investigation.

In a letter a Navy Surgeon General Vice Adm. Willard P. Arentzen. Crane noted he had complained previously about the shortages and said, "Now the disaster which I had predicted has occurred and a patient has died unnecessarily as a result of negligence on the part of anesthesiology and surgery residents."

Crane said Minor's death "could have been prevented had the required staff of anesthesiologists been available to supervise the patient's care."

Anesthesiologists are doctors who administer pain-killing drugs or gas during major operations.

After Minor's operation, Crane said in his letter, Minor was taken to an intensive care unit and placed on a respirator. Although it is customary for patients on respirators to be supervised by residents, he said. the resident responsbile for Minor was called away for an emergency childbirth operation.

Minor was buried at sca July 11. six days after Crane's letter alleging improprieties on his treatment.

In a telephone conversation Friday, Crane said he sees "nothing sinister" in the burial. "The day-to-day care of the patients here is unimpeachable." he said. "But from time to time, situations arise where there are not enough physicians around."

Crane himself has become a focus of centroversy at the medical center. A committee of graduate students has recommended that he not be allowed to complete his training there, in effect that he be fired. No decision has been made on the recommendation.

The surgeon general's investigation has already began here. Officials said a team of investigators will go to Oakland shortly.