The Eiffel Tower is "not in bad condition but is an old lady needing a checkup and probably a facelift," according to Bernard Rocher, president of a company formed this year to operate the most popular of all Paris monuments upon departure of the original concession operators.

The new managers have two years in which to make a complete analysis of the 91-year-old structure whose builder, Gustave Eiffel, thought that its construction material, cast iron, was "eternal."

Rochet said all visible parts of the tower are in good shape. Confidence in the sturdiness of the monument has led, however, to its overloading. This aspect will be carefully studied.

The 27 shops and stands selling knickknacks will probably be regrouped in the manner of modern airport shopping areas and an attempt will be made to widen the range of merchandise available.

One innovation under the new regime is that visitors who want to see the hydraulic machinery that powers one of the tower's elevators, will be given access (for an extra charge) to this monument of French engineering at the turn of the last century. It looks like the engine room of Jules Verne's imaginary submarine Nautilus in "20,000 Leagues under the Sea." It is in perfect working order.

The three hydraulic elevators which carry visitors to the first and second levels are satisfactory. But the elevator between the second level and the top is slow and uneconomical. It cannot be used in winter because of freezing.

Among immediate improvements due this summer are a new illustrated guide book, the introduction of guided tours, better signposting, proper orientation tables on the third (top) level and modern television-type viewers on the second level.

No estimated figure for the cost of renovation is yet available. Maintenance at present consumes 25 percent of gross income.

About 3.5 million people climb the Eiffel Tower annually, three-quarters of them foreigners. For many foreign visitors it is the only French monument they ever see, so the company feels it should make every effort to leave a good impression.

So far, 87,507,622 people have paid to climb the tower since it was opened in 1889.