A position sensor for a transmission mode selector lever, the position sensor comprising: a magnet including a first magnetized region and a second magnetized region; three or more magnetic flux detection elements (21, 22, 23; 24, 25, 26, 27) that detect magnetic flux of the magnet, wherein the three or more magnetic flux detection elements are arranged opposing the magnet; and a determination circuit that determines an operation position of the transmission mode selector lever based on output levels of detection signals generated by the three or more magnetic flux detection elements, the position sensor being characterized in that: the first magnetized region is formed so that when the magnet is moved relative to the three or more magnetic flux detection elements in a certain direction along a first straight line that is an operation direction of the transmission mode selector lever, output levels of the detection signals generated by the three or more magnetic flux detection elements change in accordance with a proportional relationship having a first gradient relative to the distance of the movement, the second magnetized region is formed so that when the magnet is moved in the certain direction along a second straight line that is an operation direction of the transmission mode selector lever, parallel to the first straight line, and differs from the first straight line, output levels of the detection signals generated by the three or more magnetic flux detection elements change in accordance with a proportional relationship having a second gradient relative to the distance of the movement, one of the first and second gradients is a positive value, the other one of the first and second gradients is a negative value, and the three or more detection elements are spaced apart from each other on a straight line that is parallel to the first straight line and the second straight line. a magnet including a first magnetized region and a second magnetized region; three or more magnetic flux detection elements (21, 22, 23; 24, 25, 26, 27) that detect magnetic flux of the magnet, wherein the three or more magnetic flux detection elements are arranged opposing the magnet; and a determination circuit that determines an operation position of the transmission mode selector lever based on output levels of detection signals generated by the three or more magnetic flux detection elements, the position sensor being characterized in that: the first magnetized region is formed so that when the magnet is moved relative to the three or more magnetic flux detection elements in a certain direction along a first straight line that is an operation direction of the transmission mode selector lever, output levels of the detection signals generated by the three or more magnetic flux detection elements change in accordance with a proportional relationship having a first gradient relative to the distance of the movement, the second magnetized region is formed so that when the magnet is moved in the certain direction along a second straight line that is an operation direction of the transmission mode selector lever, parallel to the first straight line, and differs from the first straight line, output levels of the detection signals generated by the three or more magnetic flux detection elements change in accordance with a proportional relationship having a second gradient relative to the distance of the movement, one of the first and second gradients is a positive value, the other one of the first and second gradients is a negative value, and the three or more detection elements are spaced apart from each other on a straight line that is parallel to the first straight line and the second straight line. the first magnetized region is formed so that when the magnet is moved relative to the three or more magnetic flux detection elements in a certain direction along a first straight line that is an operation direction of the transmission mode selector lever, output levels of the detection signals generated by the three or more magnetic flux detection elements change in accordance with a proportional relationship having a first gradient relative to the distance of the movement, the second magnetized region is formed so that when the magnet is moved in the certain direction along a second straight line that is an operation direction of the transmission mode selector lever, parallel to the first straight line, and differs from the first straight line, output levels of the detection signals generated by the three or more magnetic flux detection elements change in accordance with a proportional relationship having a second gradient relative to the distance of the movement, one of the first and second gradients is a positive value, the other one of the first and second gradients is a negative value, and the three or more detection elements are spaced apart from each other on a straight line that is parallel to the first straight line and the second straight line.