Semi Automatic PET Blow Moulding Machine is provided with hydraulic mould clamping system to enhance power efficiency. The PET Blow Moulding Machine has mechanical lock system for positive locking. The PET Blow Moulding Machine is provided with close loop heating system and auto chamber temperature control to compensate variation in preform heating due to ambient temperature. Semi Automatic PET Blow Moulding Machine has air ventilation facility with controllable venting in heating chamber for better heat penetration control.