An exemplary object is to provide a library apparatus, a magazine insertion detection method, and a program that are capable of detecting whether or not a magazine is inserted for all the magazine insertion positions without using sensors for detecting insertion of magazines. A library apparatus includes: a mark reading unit which is provided in an accessor unit which transfers a plurality of media that can be read and written by a computer, and reads a predetermined mark for all insertion positions of a plurality of magazines which can be inserted into the library apparatus and can accommodate the media, the mark being stuck to each of cells accommodating the media; and a control unit which, if the mark can be read, determines that a magazine is inserted at an insertion position which includes a read position for which a reading result that the mark can be read has been obtained, and, if the mark cannot be read, determines that no magazine is inserted at an insertion position which includes a read position for which a reading result that the mark cannot be read has been obtained.