PURPOSE: To press an insert into a molded product precisely, by adjusting the lifting circuit of the piston rod provided with a heating device by a height adjusting circuit at an insert press-in equipment in addition to the press-in mechanism which presses the insert into by the heating device.

CONSTITUTION: When moving up and down a heating device 9 to the loading bed 1 of a plastic molded product 2 and push-inserting an insert, said heating device is lowered by actuating the lowering circuit of the piston rod 5 of a cylinder 4 and the adjusting circuit of a pushing pressure, at the same time the heating device is actuated. After a certain time said piston rod lowering circuit is transferred to a high pressure lowering circuit, the insert is push-inserted and the lifting height of the heating device is automatically adjusted according to the height from the loading bed 1 to the position of an insert press-into using a lift adjusting timer and the lift adjusting auxiliary timer jointly, thereby a precise inserting is done.