To reduce the dependency of an in-focus position on an illumination wavelength of ambient light and spectral reflectance of a subject when images of visible light and infrared light are imaged.SOLUTION: An image capturing apparatus comprises: an image sensor that is sensitive to light in a first wavelength band and light in a second wavelength band which are incident via an imaging optical system; an optical filter provided between the imaging optical system and the image sensor and having a first filter region that allows the light in the first wavelength band to selectively transmit; and calculation means for calculating an in-focus position of a focus lens on the basis of a signal obtained from the image sensor. The calculation means estimates a component in the first wavelength band and a component in the second wavelength band of light received by a second pixel region on the basis of a first signal obtained from a first pixel region for receiving light that has passed through the first filter region among pixel regions of the image sensor and a second signal obtained from the second pixel region excluding the first pixel region, and calculates the in-focus position of the focus lens with respect to a predetermined imaging distance on the basis of the estimated components.SELECTED DRAWING: Figure 2