A digitizer includes a case having an input portion; at least three first projected portions fixed to the case, the first projected portions coming into contact with a placement surface so as to support the case on the placement surface; and a second projected portion arranged inside of an area defined by connecting the points at which the first projected portions are fixed to the case. The second projected portion is configured such that, when a force substantially parallel to the placement surface is applied to the case, the first projected portions slide against the placement surface so that the case rotates relative to the placement surface with the second projected portion as a rotation axis.