The object of the invention is a method for modernizing an elevator, and a traction sheave elevator, which elevator comprises at least an elevator car and a traction sheave that moves the elevator car by means of elevator ropes, the rim of which traction sheave comprises one or more rope grooves. In connection with modernization a traction sheave is installed as the traction sheave of the elevator, the rope grooves of which traction sheave comprise a material, the frictive traction achieved by which is greater than the frictive traction between the parent material of the metallic traction sheave and the elevator ropes.