PURPOSE: To enable a machine to prevent its vibration and/or change of torque from being generated, by forming a communication path, through which two working chambers communicate when they are in a delivery stroke, in the end plate of a fixed scroll so as to hold pressure balance between the both working chambers.

CONSTITUTION: A fluid machine forms a communication path 6, through which two working chambers communicate when they are in a delivery stroke, in an end plate 21 of a fixed scroll 2. In this way, a change of driving torque in a scroll compressor and/or its generated vibration are prevented from being generated by relaxing the unbalance of internal pressure in the both working chambers even if their outflow resistance generates a difference due to an opening degree of delivery ports when the both working chambers are in a delivery stroke.