A method for producing an optical part includes an irradiation process for irradiating a radiation-sensitive polymerizable composition with a radiation. The radiation-sensitive polymerizable composition includes at least a polymerizable compound (a) and a polymerizable or non-polymerizable component (c). The irradiation process includes at least a first step of irradiating with a radiation only a first irradiation region that is a portion of the radiation-sensitive polymerizable composition and a second step of irradiating with a radiation only a second irradiation region that is a portion of the radiation-sensitive polymerizable composition and is different from the first irradiation region in at least one of size and position. When the component (c) is polymerizable, the polymerization rate of the component (c) is controlled to be lower than that of the polymerizable compound (a) in the first and the second steps.