A position detection apparatus that is mounted on a movable body and is configured to detect a low position (R2; G) that is a position lower than a road surface (R1; R11) on which the movable body is present, the position detection apparatus comprising: a stereo camera; an image processing section configured to acquire a parallax image (dp) in which a parallax is associated with each pixel from an image captured by the stereo camera and to select an area for detecting said low position in the parallax image (dp); said image processing section configured to vote the parallax associated with each pixel in the parallax image (dp) to a two-dimensional matrix representing the frequencies of the parallaxes associated with pixels having the same vertical pixel coordinate, said matrix having a first direction corresponding to parallax and ranging from 1 to a maximum value (d) of the parallax in the area, and a second direction corresponding to a pixel in a vertical direction in the parallax image (dp) and ranging from 1 to a maximum value (v) of a pixel in the vertical direction; said image processing section being further configured to extract one or more lines from a coordinate system with an X-axis indicating said parallax and a Y-axis indicating said pixel in the vertical direction, in which the parallax having the number of votes that is greater than or equal to a 1 threshold value is plotted; and said image processing section being further configured such that, in a case where a first line and a second line are detected by said image processing section, an X-coordinate of the start point coordinates (x2, y2) of the second line is greater than an X-coordinate of end point coordinates (x1, y1) of the first line, wherein a start point has the coordinates of a line which has the smallest pixel in a vertical direction, and an end point has the coordinates of a line which has the greatest pixel in a vertical direction, and a difference between a slope of the first line and a slope of the second line falls within a permissible range (S6: YES), said image processing section is configured to determine that the low position (R2; G) is present at a position farther from the movable body than a position in real space that corresponds to a Y-coordinate of start point coordinates (x2, y2) of the second line. a stereo camera; an image processing section configured to acquire a parallax image (dp) in which a parallax is associated with each pixel from an image captured by the stereo camera and to select an area for detecting said low position in the parallax image (dp); said image processing section configured to vote the parallax associated with each pixel in the parallax image (dp) to a two-dimensional matrix representing the frequencies of the parallaxes associated with pixels having the same vertical pixel coordinate, said matrix having a first direction corresponding to parallax and ranging from 1 to a maximum value (d) of the parallax in the area, and a second direction corresponding to a pixel in a vertical direction in the parallax image (dp) and ranging from 1 to a maximum value (v) of a pixel in the vertical direction; said image processing section being further configured to extract one or more lines from a coordinate system with an X-axis indicating said parallax and a Y-axis indicating said pixel in the vertical direction, in which the parallax having the number of votes that is greater than or equal to a 1 threshold value is plotted; and said image processing section being further configured such that, in a case where a first line and a second line are detected by said image processing section, an X-coordinate of the start point coordinates (x2, y2) of the second line is greater than an X-coordinate of end point coordinates (x1, y1) of the first line, wherein a start point has the coordinates of a line which has the smallest pixel in a vertical direction, and an end point has the coordinates of a line which has the greatest pixel in a vertical direction, and a difference between a slope of the first line and a slope of the second line falls within a permissible range (S6: YES), a first line and a second line are detected by said image processing section, an X-coordinate of the start point coordinates (x2, y2) of the second line is greater than an X-coordinate of end point coordinates (x1, y1) of the first line, wherein a start point has the coordinates of a line which has the smallest pixel in a vertical direction, and an end point has the coordinates of a line which has the greatest pixel in a vertical direction, and a difference between a slope of the first line and a slope of the second line falls within a permissible range (S6: YES), said image processing section is configured to determine that the low position (R2; G) is present at a position farther from the movable body than a position in real space that corresponds to a Y-coordinate of start point coordinates (x2, y2) of the second line.