To provide a voltage detection circuit in which a general-purpose semiconductor element and an IC is used with a minimum number of times of usage of high-precision resistor since a terminal voltage of each battery cell is required to be monitored in the case where a battery cell such as lithium ion is used as a battery pack.

An output current of one variable constant current source 2 placed at a reference potential of positive or negative electrode of a battery pack 1 is switched and supplied to each battery cell potential by a current selector 3. The terminal voltage of each battery cell is compared, for level, with a voltage having been converted from the output current using resistors R4-2 to R4-n for each of battery cells B1-Bn, and the result is detected at the reference potential. The output current is changed while monitoring a result of comparison for level, and the terminal voltage of the battery cell is detected from the output current at the time point when the comparison result is reversed. In this circuit configuration, an OP amplifier and comparator, being a general-purpose IC, are used, with a minimum number of times of usage of high-precision resistor.