According to one embodiment, in the angle detection apparatus, the first A-D converter unit receives the first signal, and performs analog-to-digital conversion of the first signal. The second A-D converter unit receives the second signal orthogonal to the first signal, and performs analog-to-digital conversion of the second signal. The first delay circuit receives a third signal outputted by the first A-D converter unit, and performs a phase adjustment of the third signal. The second delay circuit receives a fourth signal outputted by the second A-D converter unit, and performs a phase adjustment of the fourth signal. The phase detection adjustment unit monitors phases of signals outputted by the first and second delay circuits, and gives phase adjustment commands to the first and second delay circuits, when a phase shift occurs.