[Problem] To provide a dimension measurement device capable of accurately measuring medicine dimensions without being influenced by changes in the use environment. [Solution] This dimension measurement device S1 comprises: a light source unit L, a photography unit C, a medicine holding unit H for holding medicine 1 between the photography unit C and light source unit L such that the medicine 1 can be photographed from different directions, a light-source-output adjustment unit U1 for adjusting the luminance of the light source unit L on the basis of the brightness of a photographed image photographed by the photography unit C, and a shape measurement unit U2 for measuring the X dimension and Y dimension of the medicine 1 in mutually orthogonal X direction and Y direction in a photographed image photographed after luminance adjustment has been carried out at least once.
