An apparatus includes: a current control unit to control an amount of constant current and supply a first and second constant currents to an infrared detection pixel; a constant current supply time control unit to control periods of time in which the first and second constant currents are supplied to the infrared detection pixel; an A-D converter to convert a first and second electrical signals from the infrared detection pixel into a first and second digital signals, the first and second electrical signals being generated when the first and second constant currents is supplied to the infrared detection pixel, respectively; a subtracting unit to calculate a difference between the first and second digital signals; and a determining unit to determine whether the infrared detection pixel is a defective pixel based on the absolute value of the difference calculated by the subtracting unit.