The present invention provides a static pressure type non-contact gas seal which, even when supply of seal gas 6 to the space between sealing end surfaces 3a and 4a has stopped unexpectedly, can be safely used with no possibility that the sealing end surfaces 3a and 4a collide severely against each other and consequently the sealing end surfaces 3a and 4a are damaged or destructed. In this static pressure type non-contact gas seal, the seal gas 6 is supplied to the space between the sealing end surfaces 3a and 4a from a seal gas passage 5, thereby generating an opening force that acts on the stationary sealing ring 4 in a direction that the space between the sealing end surfaces 3a and 4a is opened. An annular-spaced back pressure chamber 25 blocked by two O-rings 12 and 13 is formed between the facing peripheral surfaces of a seal case 1 and the stationary sealing ring 4, to introduce the seal gas 6 to be supplied to the seal gas passage 5 into the back pressure chamber 25, thereby generating a closing force that maintain the balance with the opening force, as a back pressure acting on the stationary sealing ring 4. A spring is not used as a means for generating the closing force.