To provide a switching operation detection apparatus capable of preventing malfunction arising when a plug is pulled out.

When a flag 1 is not "1" (S3: No), it indicates that a level of an input port 1 is changed from low to high, and then, it is determined whether a flag 2 is set at "1" (S5). When the flag 2 is not set at "1" (S5: No), a level of an input port 2 is low, and then, it is determined whether a flag 3 is set at "1" (S6). When a flag 3 is "1" (S6: Yes), it indicates that the plug 21 is inserted into a jack 6, and therefore, it is determined that a first switch FSW1 is switched on, and starting processing or stopping processing of automatic playing is performed (S7).