The invention is to provide a resistor trimming method capable of adjusting a resistance value with ultrahigh precision and having excellent production efficiency. To achieve the object, a start point (S1) at a distance from a resistor (4) is irradiated with laser light while probes are brought into contact with a pair of surface electrodes (3) to measure a resistance value of the resistor (4). The place irradiated with the laser light is scanned so that a first trimming groove (5) extending in a direction perpendicular to a current direction can be formed in the resistor (4). Then, the place irradiated with the laser light is returned by a predetermined amount from an end point (first turning point (T1)) of the first trimming groove (5) to be set as a second turning point (T2). With the second turning point (T2) as a start point, scanning and cutting is performed to forma second trimming groove (6). Thus, the resistance value of the resistor (4) is adjusted to a target resistance value with high precision.