A rotating electric machine for vehicular use, comprising: a stator that includes a stator core and a stator winding wound at the stator core; and a rotor that is rotatably disposed relative to the stator and includes a rotor core formed by laminating a plurality of electromagnetic steel sheets with a plurality of magnet insertion holes formed therein and includes a plurality of permanent magnets (254, 255) each held in each of the plurality of magnet insertion holes to form a magnetic pole, wherein: each of the plurality of permanent magnets (254, 255) extends along a rotor axis and is formed in a shape assuming at least two different lengths along a circumference of the rotor; each of the plurality of permanent magnets (254, 255) is constituted with n (n is an integer equal to or greater than 2) types of rectangular parallelepiped shaped magnet pieces (254a-d, 255a-d) set side-by-side along the rotor axis; and the n types of magnet pieces (254a-d, 255a-d) assume lengths along the circumference of the rotor that are different from one another, and the n types of magnet pieces (254a-d, 255a-d) are disposed so that central lines running through centers of the magnet pieces (254a-d, 255a-d), assumed along the circumference of the rotor, form a substantially single straight line running along the rotor axis, characterized in that the lengths are different from one another by an extent equivalent to approximately 60°/ n in electrical angle. a stator that includes a stator core and a stator winding wound at the stator core; and a rotor that is rotatably disposed relative to the stator and includes a rotor core formed by laminating a plurality of electromagnetic steel sheets with a plurality of magnet insertion holes formed therein and includes a plurality of permanent magnets (254, 255) each held in each of the plurality of magnet insertion holes to form a magnetic pole, wherein: each of the plurality of permanent magnets (254, 255) extends along a rotor axis and is formed in a shape assuming at least two different lengths along a circumference of the rotor; each of the plurality of permanent magnets (254, 255) is constituted with n (n is an integer equal to or greater than 2) types of rectangular parallelepiped shaped magnet pieces (254a-d, 255a-d) set side-by-side along the rotor axis; and the n types of magnet pieces (254a-d, 255a-d) assume lengths along the circumference of the rotor that are different from one another, and the n types of magnet pieces (254a-d, 255a-d) are disposed so that central lines running through centers of the magnet pieces (254a-d, 255a-d), assumed along the circumference of the rotor, form a substantially single straight line running along the rotor axis, each of the plurality of permanent magnets (254, 255) extends along a rotor axis and is formed in a shape assuming at least two different lengths along a circumference of the rotor; each of the plurality of permanent magnets (254, 255) is constituted with n (n is an integer equal to or greater than 2) types of rectangular parallelepiped shaped magnet pieces (254a-d, 255a-d) set side-by-side along the rotor axis; and the n types of magnet pieces (254a-d, 255a-d) assume lengths along the circumference of the rotor that are different from one another, and the n types of magnet pieces (254a-d, 255a-d) are disposed so that central lines running through centers of the magnet pieces (254a-d, 255a-d), assumed along the circumference of the rotor, form a substantially single straight line running along the rotor axis, characterized in that the lengths are different from one another by an extent equivalent to approximately 60°/ n in electrical angle.