A distance measurement system, comprising: a projection apparatus which is a light projection apparatus, and which is adapted to project measurement beams (PL1, PL2) at least at first and second projection angles (α3, α15, α, β) towards a detection area; an image pick-up apparatus which is adapted to pick up an image of a first reflected light and an image of a second reflected light from the detection area and is adapted to output image signals (s(t)), the first reflected light corresponding to the measurement beam projected at the first projection angle (α3, α), and the second reflected light corresponding to the measurement beam projected at the second projection angle (α15, β); and a distance calculation unit which, based on the image signals (s(t)), is adapted to calculate a first distance to a first measurement point (P2, P5) from a first incidence angle (γ) of the first reflected light onto the image pick-up apparatus, the first projection angle (α3, α) and an inter-apparatus distance (e) between the projection apparatus and the image pick-up apparatus, and is adapted to calculate a second distance to a second measurement point (P4, P7) from a second incidence angle (γ) of the second reflected light onto the image pick-up apparatus, the second projection angle (α15, β) and the inter-apparatus distance (e); characterized by: a judgment unit which is adapted to judge that specular reflection is caused when the first incidence angle (γ) of the first reflected light is equal to the second incidence angle (γ) of the second reflected light, wherein the judgment unit is additionally adapted to judge whether multiple reflection is present, which is the case when there is one ore more specular reflection; and an operation unit which, when it is judged by the judgment unit that the specular reflection is caused, is adapted to calculate a distance to a detection object (MB1, MB2) causing the specular reflection based on a longest distance among the first distance to the first measurement point (P2, P5) and the second distance to the second measurement point (P4, P7) and the first and second projection angles (α3, α15, α, β) when the first and second incidence angles (γ) are judged to be equal to each other. a projection apparatus which is a light projection apparatus, and which is adapted to project measurement beams (PL1, PL2) at least at first and second projection angles (α3, α15, α, β) towards a detection area; an image pick-up apparatus which is adapted to pick up an image of a first reflected light and an image of a second reflected light from the detection area and is adapted to output image signals (s(t)), the first reflected light corresponding to the measurement beam projected at the first projection angle (α3, α), and the second reflected light corresponding to the measurement beam projected at the second projection angle (α15, β); and a distance calculation unit which, based on the image signals (s(t)), is adapted to calculate a first distance to a first measurement point (P2, P5) from a first incidence angle (γ) of the first reflected light onto the image pick-up apparatus, the first projection angle (α3, α) and an inter-apparatus distance (e) between the projection apparatus and the image pick-up apparatus, and is adapted to calculate a second distance to a second measurement point (P4, P7) from a second incidence angle (γ) of the second reflected light onto the image pick-up apparatus, the second projection angle (α15, β) and the inter-apparatus distance (e); characterized by: a judgment unit which is adapted to judge that specular reflection is caused when the first incidence angle (γ) of the first reflected light is equal to the second incidence angle (γ) of the second reflected light, wherein the judgment unit is additionally adapted to judge whether multiple reflection is present, which is the case when there is one ore more specular reflection; and an operation unit which, when it is judged by the judgment unit that the specular reflection is caused, is adapted to calculate a distance to a detection object (MB1, MB2) causing the specular reflection based on a longest distance among the first distance to the first measurement point (P2, P5) and the second distance to the second measurement point (P4, P7) and the first and second projection angles (α3, α15, α, β) when the first and second incidence angles (γ) are judged to be equal to each other.