a scroll type fluid machine having two scroll members each having an end plate and a spiral wrap formed on the end plate , the scroll members being coupled to each other such that the wraps thereof mate with each other . one of two scroll members being adapted to make an orbitary movement with respect to the other scroll member while being prevented from rotating around its own axis , so as to form at least one working chamber of different pressures between two scroll members . at least two pressing force imparting chambers are formed on the opposite side of the orbitary scroll member to the wrap . the pressing force imparting chambers includes a first chamber which is communicated through a communication passage with at least one of the working chambers which is not materially communicating with a low pressure port and is not at all communicating with a high pressure port of the machine , and a second chamber which is communicated with the high pressure port through a communication passage , so that fluid pressures of different levels are applied to the first and second pressing force imparting chambers so as to produce a force which presses the orbitary scroll member to the other scroll member .