A traffic signal detection device comprising: a camera configured to capture an image of surroundings of a mobile object and fixed to the mobile object such that an angle of view and an image capturing direction of the camera with respect to the mobile object is determined; a self-position detector configured to detect a position of the mobile object on a map; a traffic signal position estimation unit configured to estimate a relative position of a traffic signal with respect to the mobile object on the basis of map information including positional information of the traffic signal that is present on the surroundings of the mobile object, the position of the mobile object on the map, and a travelling direction of the mobile object; a first detection region setting unit configured to set a first detection region on the image for each traffic signal predicted to be present on the image, based on the relative position of the traffic signal with respect to the camera; and a traffic signal detector configured to detect traffic signals, characterized by a second detection region setting unit configured to set, when it is predicted that a plurality of traffic signals is present on the image, a second detection region on the image including all of the plurality of traffic signals, based on the relative positions of the traffic signals with respect to the camera; a lamp detector configured to detect, from the second detection area, a lamp candidate having a feature of a lamp of a traffic signal; and a third detection region setting unit configured to set a third detection region for each of the plurality of traffic signals by correcting a position of the first detection region to cause the position of the first detection region by using at least one of translating, rotational movement, and scaling, so as to correspond to the lamp candidate, wherein the traffic signal detector is configured to detect traffic signals from the third detection region. a camera configured to capture an image of surroundings of a mobile object and fixed to the mobile object such that an angle of view and an image capturing direction of the camera with respect to the mobile object is determined; a self-position detector configured to detect a position of the mobile object on a map; a traffic signal position estimation unit configured to estimate a relative position of a traffic signal with respect to the mobile object on the basis of map information including positional information of the traffic signal that is present on the surroundings of the mobile object, the position of the mobile object on the map, and a travelling direction of the mobile object; a first detection region setting unit configured to set a first detection region on the image for each traffic signal predicted to be present on the image, based on the relative position of the traffic signal with respect to the camera; and a traffic signal detector configured to detect traffic signals, characterized by a second detection region setting unit configured to set, when it is predicted that a plurality of traffic signals is present on the image, a second detection region on the image including all of the plurality of traffic signals, based on the relative positions of the traffic signals with respect to the camera; a lamp detector configured to detect, from the second detection area, a lamp candidate having a feature of a lamp of a traffic signal; and a third detection region setting unit configured to set a third detection region for each of the plurality of traffic signals by correcting a position of the first detection region to cause the position of the first detection region by using at least one of translating, rotational movement, and scaling, so as to correspond to the lamp candidate, wherein the traffic signal detector is configured to detect traffic signals from the third detection region.