Linear motor capable of reducing the cogging force when the motor is operated

A linear motor includes a magnet holder, a magnet unit, a coil holder, a coil unit and a power transmission unit. The magnet unit is disposed on the magnet holder and includes a plurality of magnet sets. Each magnet set has two magnets. A plurality of magnet center lines respectively corresponding to the magnet sets are defined. Each of the magnet center lines passes through a geometric center of the magnets of each magnet set. Each of the magnet center lines is a straight line or a turning line. The coil unit is disposed on the coil holder and includes a plurality of coil sets. Each coil set has two coils. A plurality of coil center lines respectively corresponding to the coil sets are defined. Each of the coil center lines passes through a geometric center of the coils of each coil set. Each of the coil center lines is a straight line or a turning line. The design of the invention can effectively reduce the cogging force when the motor is operated.