The present invention aims at improving the efficiency of tool management by improving the arrangement of a tool magazine in a composite working lathe. The composite working lathe 1 includes a spindle stock and a tool spindle disposed on a bed 20, and a cover 2 covering the surrounding area thereof. A door 4 allowing access to a machining portion is provided on a front side F of the machine, and the machining portion can be visually observed through a window 5. A tool magazine unit 100 is disposed in front of the spindle stock of the machine. A door 120 and a window 130 are provided on the cover of the tool magazine unit 100, allowing operators to observe the tool stored in the magazine through windows 122 and 130. The present composite working lathe enables to improve the efficiency of tool management, such as the confirmation of the tool used in the subsequent step or the removal of chips on the used tool.