A cryogenic refrigerator includes a Scotch yoke mechanism including a Scotch yoke and a bearing movably engaged with the Scotch yoke, and a displacer caused to reciprocate in a cylinder by the Scotch yoke mechanism, so that a refrigerant gas inside an expansion space formed in the cylinder is expanded by the reciprocation of the displacer to generate cold temperatures. The Scotch yoke includes a concave part at a position corresponding to a top dead center of the displacer.