PURPOSE: To make simultaneous dyeing of many pieces of plastic lenses possible by controlling a vertically moving shaft with a cam and a lever thereby setting the conditions suited for required dyeing condition.

CONSTITUTION: The starting position of a mounting shaft 5 provided with many lens mounting jigs 4 is adjusted according to the liquid level of a dyeing soln. 12. Then, when a cam 10 is turned, a mounting shaft 5 is oscillated vertically by a cam lever 9, a vertically moving shaft 8, etc. The lenses 1 are moved at the vertical amplitude at which the deepest faces thereof come to the centerline of the lenses in such a way that the dipping surfaces shift stepwise below the lenses, whereby half dyeing of the lenses 1, etc. are accomplished. By such constitution, the many plastic lenses are dyed simultaneously with good reproducibility and quality in the dyeing state of the same conditions.