A resolver includes an excitation coil for receiving an excitation signal and a detection coil for outputting a detection signal. The detection sine wave is changeable according to an amount of displacement of a movable element provided in the excitation coil or the detection coil. The resolver detects the amount of displacement of the movable element based on the excitation signal and the detection signal. The detection coil is one coil formed of a first detection coil pattern and a second detection coil pattern connected in series or in parallel such that the second detection coil pattern is shifted in phase by a half cycle from the first detection coil pattern.