Fastening member and compressor apparatus

The present invention provides a fastening member and a compressor apparatus capable of improving workability of assembling. A fastening member (20) includes a bolt (30) and a nut (32) for attaching a compressor to a vehicle body. A non-circular relative rotation prevention portion (30B) is formed below a head portion (30A) of the bolt (30). A washer (31) is non-rotatably press fitted around the relative rotation prevention portion. Before the attachment, the head portion (30A) and the washer (31) are temporarily fixed with a space generated therebetween. An elastic body (33), which is attached to the compressor, is disposed between the washer (31) and the nut (32). A cylindrical member (34) is provided at an inner circumference of the elastic body (33). As a result, when the nut (32) is screwed, an axial force of the nut (32) is transmitted to the washer (31) via the cylindrical member (34), and the space between the washer (31) and the head portion (30A) reduces, completing the attachment.