Method for determining whether a component holder is defective

A component mounting method comprising:

• performing a component mounting operation that includes using a component holder to hold a component and mount said component onto a circuit board;
• and
• after performing said component mounting operation a set number of times, determining whether or not said component holder is defective by
• (i) illuminating a component hold face of a component holder by emitting light to said component holder, said component hold face having an area greater than an area of a light reflection face of a component held by said component holder, wherein said component hold face corresponds to a surface of said component holder that faces a surface of said component held by said component holder, and wherein said light reflection face corresponds to a surface of said component other than said surface of said component that faces said component hold face,
• (ii) performing image-pickup of said component hold face, when illuminated by emitting the light to said component holder, so as to provide image-pickup information of said component hold face when illuminated by emitting the light to said component holder, and
• (iii) determining that said component holder is defective when luminance of a non-cover region of said component hold face, based on said image-pickup information, is not smaller than a setting value, wherein said non-cover region corresponds to a region of said component hold face other than a region of said component hold face covered by said another component,
• wherein said non-cover region of said component hold face is divided into sections, each of which has said setting value, such that, determining that said component holder is defective comprises determining that said component holder is defective when luminance of at least one of said sections of said non-cover region, based on said image-pickup information, is not smaller than said setting value.