A lower spring sheet (11) has receiving portions (15a, 15b) on a sheet surface (14) that supports a coil spring (13). Thus the sheet surface (14) and a spring end portion (13a) of the coil spring (13) come into contact discretely. The contact positions between the coil spring (13) and the sheet surface (14) maintain unchanged, however a undulated portion the spring end portion (13a) may have due to the manufacturing tolerance is extended when the coil spring (13) is compressed. <IMAGE>
