PURPOSE: To make the AE behavior clear and evaluate the damage in a composite material part based on the measurement result by installing an AE sensor for sensing acoustic emission and a temperature control mechanism for setting the optimum heat treatment time corresponding to the molding condition.

CONSTITUTION: The measurement of acoustic emission is carried out in the heat treatment of a composite material part, and the heat treatment process is repeated by feeding back on the heat treatment oven side until the total count of AE in the heat treatment comes less than a reference total AE count. Also the AE event number in the stabilized zone of AE event number is compared with the reference AE event number. The setting of heat treatment condition corresponding to the molding condition of the composite material part can be carried out automatically by said arrangement, and also the evaluation of damage in the composite material part can be performed simultaneously.