An optimizer includes a processor configured to: optimize a change amount of a interlinkage magnetic flux in a coil by using an objective function formula that maximizes a sum of Δφirightxi (i=1 to Nc) and Δφileftyi (i=1 to Nc), when it is assumed that a surface of the magnetic device where the coil is arranged be divided into Nc (Nc is integer) coil regions, in an i-th coil region Ni, an auxiliary variable of a clockwise coil that may exist in the coil region Ni be xi, and an auxiliary variable of a counterclockwise coil that may exist in the coil region Ni be yi, and a change amount of an interlinkage magnetic flux of the clockwise coil in the coil region Ni be Δφiright and a change amount of an interlinkage magnetic flux of the counterclockwise coil in the coil region Ni be Δφileft.