A light source position detection apparatus, comprising: a condensing section (32, 51a, 61) that condenses light emitted from a light source to be detected; an image pickup device that receives the light condensed by the condensing section (32, 51a, 61); infrared light image forming means for forming an image of infrared light that passes through clouds on the image pickup device, out of light emitted from the light source to be detected without forming any image of visible light on the image pickup device; and a control section, wherein the control section performs: a first acquisition process of acquiring per-pixel brightness information from the image pickup device; a process of changing a shutter speed based on the brightness information acquired in the first acquisition process and adjusting the quantity of light received by the image pickup device; a second acquisition process of acquiring per-pixel brightness information from the image pickup device, the shutter speed of which is changed; a process of setting brightness information equal to or less than a threshold set to a value greater than brightness caused by light scattered by clouds out of the brightness information acquired in the second acquisition process to zero; and a process of detecting the position of the light source to be detected based on brightness information after the setting to zero process. a condensing section (32, 51a, 61) that condenses light emitted from a light source to be detected; an image pickup device that receives the light condensed by the condensing section (32, 51a, 61); infrared light image forming means for forming an image of infrared light that passes through clouds on the image pickup device, out of light emitted from the light source to be detected without forming any image of visible light on the image pickup device; and a control section, wherein the control section performs: a first acquisition process of acquiring per-pixel brightness information from the image pickup device; a process of changing a shutter speed based on the brightness information acquired in the first acquisition process and adjusting the quantity of light received by the image pickup device; a second acquisition process of acquiring per-pixel brightness information from the image pickup device, the shutter speed of which is changed; a process of setting brightness information equal to or less than a threshold set to a value greater than brightness caused by light scattered by clouds out of the brightness information acquired in the second acquisition process to zero; and a process of detecting the position of the light source to be detected based on brightness information after the setting to zero process. a first acquisition process of acquiring per-pixel brightness information from the image pickup device; a process of changing a shutter speed based on the brightness information acquired in the first acquisition process and adjusting the quantity of light received by the image pickup device; a second acquisition process of acquiring per-pixel brightness information from the image pickup device, the shutter speed of which is changed; a process of setting brightness information equal to or less than a threshold set to a value greater than brightness caused by light scattered by clouds out of the brightness information acquired in the second acquisition process to zero; and a process of detecting the position of the light source to be detected based on brightness information after the setting to zero process.