In a curved spring configured to generate, based on a relative approaching displacement of the one-side bearing section and the other-side bearing section in an approach/separation direction, an urging force in a separation direction in which a one-side bearing section and an other-side bearing section are separated from each other, a linear elastic body is provided to extend on a closed curve, which includes a one-side portion arranged along a circumferential direction of the one-side bearing section and an other-side portion arranged along a circumferential direction of the other-side bearing section, and to constitute elastic sections of two lines between the one-side portion and the other-side portion.