PURPOSE: To provide a thermoplastic resin blow molding machine good in assembling adjustment and service characteristics such as maintenance control or the like.

CONSTITUTION: A heating device for conditioning a preform and a blow device for blow-molding the preform to form a container are provided and at least one control disc 12 able to be biased forcibly is provided in order to control at least one blow station arranged to the region of the blow device. The control disc 12 is forcibly biased with respect to a follower disc 13 by at least one air pressure spring formed from the piston 22 receiving action from a diaphragm 23 and connected to a pressure discharge device capable of being subjected to service operation regardless of pressure.