A short-circuit detection circuit adapted to detect a short circuit of a signal line connected to a resolver in which an exciting signal is sent to an exciter coil and two detection signals of sine-phase and cosine-phase electromagnetically induced in two detection coils (12, 13) are output, wherein the short-circuit detection circuit comprises: an exciting-line malfunction detection circuit adapted to detect at least one of a short circuit to ground and a short circuit to a power supply of a signal line for the exciting signal, and adapted to output an exciting-line malfunction detection signal indicating a result of the detection of the short circuit; characterized in that the exciting-line malfunction detection circuit comprises: a comparator adapted to compare the potentials at both ends of the exciter coil to which the exciting signal is sent by a push-pull method to generate an exciting pulse signal that is a rectangular-wave indicating a result of the comparison of the potentials at both ends of the exciter coil, and adapted to output the generated exciting pulse signal; a duty-cycle detection section adapted to receive the exciting pulse signal, and adapted to extract and output a value corresponding to the duty cycle of the exciting pulse signal; and a threshold comparison section adapted to receive the value corresponding to the duty cycle of the exciting pulse signal, adapted to compare the value corresponding to the duty cycle of the exciting pulse signal with at least one of a value corresponding to a predetermined lower limit and a value corresponding to a predetermined upper limit to detect at least one of a short circuit to the ground and a short circuit to the power supply of the signal line for the exciting signal, and adapted to output a result of the comparison as the exciting-line malfunction detection signal. an exciting-line malfunction detection circuit adapted to detect at least one of a short circuit to ground and a short circuit to a power supply of a signal line for the exciting signal, and adapted to output an exciting-line malfunction detection signal indicating a result of the detection of the short circuit; characterized in that the exciting-line malfunction detection circuit comprises: a comparator adapted to compare the potentials at both ends of the exciter coil to which the exciting signal is sent by a push-pull method to generate an exciting pulse signal that is a rectangular-wave indicating a result of the comparison of the potentials at both ends of the exciter coil, and adapted to output the generated exciting pulse signal; a duty-cycle detection section adapted to receive the exciting pulse signal, and adapted to extract and output a value corresponding to the duty cycle of the exciting pulse signal; and a threshold comparison section adapted to receive the value corresponding to the duty cycle of the exciting pulse signal, adapted to compare the value corresponding to the duty cycle of the exciting pulse signal with at least one of a value corresponding to a predetermined lower limit and a value corresponding to a predetermined upper limit to detect at least one of a short circuit to the ground and a short circuit to the power supply of the signal line for the exciting signal, and adapted to output a result of the comparison as the exciting-line malfunction detection signal. a comparator adapted to compare the potentials at both ends of the exciter coil to which the exciting signal is sent by a push-pull method to generate an exciting pulse signal that is a rectangular-wave indicating a result of the comparison of the potentials at both ends of the exciter coil, and adapted to output the generated exciting pulse signal; a duty-cycle detection section adapted to receive the exciting pulse signal, and adapted to extract and output a value corresponding to the duty cycle of the exciting pulse signal; and a threshold comparison section adapted to receive the value corresponding to the duty cycle of the exciting pulse signal, adapted to compare the value corresponding to the duty cycle of the exciting pulse signal with at least one of a value corresponding to a predetermined lower limit and a value corresponding to a predetermined upper limit to detect at least one of a short circuit to the ground and a short circuit to the power supply of the signal line for the exciting signal, and adapted to output a result of the comparison as the exciting-line malfunction detection signal.