A spring provided between a first member and a second member, comprising: a main body portion (10, 20) having a hole portion; a cylindrical portion (11, 12) provided at a radially inner circumference and a radially outer circumference of the main body portion (10, 20); and a corner portion (13, 14) formed at a boundary portion between the main body portion (10, 20) and the cylindrical portions (11, 12); wherein the main body portion (10, 20) is extended to a crossing direction with respect to a direction in which the spring is compressed from the first member and the second member, each of the cylindrical portions (11, 12) has an abutting portion protruding from each circumference of the main body portion (10, 20) toward one of the first and the second members (101, 102) and abutting thereat, characterized in that the corner portions (13, 14) are portions which are formed such that the boundary portions between the main body portion (10, 20) and the cylindrical portions (11, 12) are bent, wherein when the spring is compressed, the corner portions (13, 14) are elastically deformed such that angles (α, β) of the corner portions (13, 14) are varying, the angles (α, β) being at sides of the first and the second members (101, 102) on which the abutting portions abut, and wherein the corner portions (13, 14) define tangent lines (U, V) along the main body portion (10, 20), and a cross-sectional surface of the main body portion contains at least one S-shaped cross section, whereby at least one of the tangent lines (U, V) has a predetermined angle (θ1, θ2) with respect to a straight line between the radially inner circumference and the radially outer circumference of the main body portion (10, 20). a main body portion (10, 20) having a hole portion; a cylindrical portion (11, 12) provided at a radially inner circumference and a radially outer circumference of the main body portion (10, 20); and a corner portion (13, 14) formed at a boundary portion between the main body portion (10, 20) and the cylindrical portions (11, 12); wherein the main body portion (10, 20) is extended to a crossing direction with respect to a direction in which the spring is compressed from the first member and the second member, each of the cylindrical portions (11, 12) has an abutting portion protruding from each circumference of the main body portion (10, 20) toward one of the first and the second members (101, 102) and abutting thereat, characterized in that the corner portions (13, 14) are portions which are formed such that the boundary portions between the main body portion (10, 20) and the cylindrical portions (11, 12) are bent, wherein when the spring is compressed, the corner portions (13, 14) are elastically deformed such that angles (α, β) of the corner portions (13, 14) are varying, the angles (α, β) being at sides of the first and the second members (101, 102) on which the abutting portions abut, and wherein the corner portions (13, 14) define tangent lines (U, V) along the main body portion (10, 20), and a cross-sectional surface of the main body portion contains at least one S-shaped cross section, whereby at least one of the tangent lines (U, V) has a predetermined angle (θ1, θ2) with respect to a straight line between the radially inner circumference and the radially outer circumference of the main body portion (10, 20).