A USB compatible apparatus for connecting an optical universal serial bus (USB) (or an optical serial bus; OSB) device and an electrical USB device, and a structure of the apparatus are provided. More particularly, a USB compatible apparatus for guaranteeing a connection between an optical USB device for inputting/outputting an optical signal and an electrical USB device for inputting/outputting an electrical signal, for example, signal transmission and reception between an electrical USB device (e.g., an electrical USB memory) and an optical USB device (e.g., a computer) having an optical USB port, and a structure of the USB compatible apparatus (a first exemplary embodiment), and a USB compatible apparatus for guaranteeing signal transmission and reception between an optical USB device (e.g., an optical USB memory) and an electrical USB device (e.g., a portable telephone) having an electrical USB port, and a structure of the USB compatible apparatus (a second exemplary embodiment) are provided.