A shoe sole comprises a bottom surface including a plurality of grooves arranged in a longitudinal direction of the shoe sole for engaging the engagement parts 6a, 6b that are formed parallel to the pedal shaft 8 of the bicycle pedal, and a protrusion having a ground contact surface between the grooves adjacent in the longitudinal direction, the sole characterized in that the protrusion has a width W2 in the longitudinal direction on an inner side in the left-right direction with respect to both feet of a wearer that is wider than a width W1 on an outer side in the left-right direction with respect to both feet of a wearer.