The present invention provides a coil spring, in which a corresponding portion is provided at an end portion in a direction of a coil axis, the corresponding portion having a whole size in the direction of the coil axis of the plurality of wire materials adjacent to each other in the direction of the coil axis equal to a maximum value of a gap in the direction of the coil axis between wire materials adjacent to each other in the direction of the coil axis of the coil spring, a gap in the direction of the coil axis between the corresponding portion and a wire material adjacent to the corresponding portion on an inner side in the direction of the coil axis is smaller than a wire height in an active coil portion of the coil spring, and at the end portion of the direction of the coil axis, a gap in the direction of the coil axis between a portion extending around the coil axis from the corresponding portion to a distal end portion side of the wire material and a wire material adjacent to the portion on the inner side in the direction of the coil axis gradually decreases from the corresponding portion toward the distal end portion side of the wire material around the coil axis.