To provide a spot welding method capable of ensuring the sufficient welding strength without any welding detachment or tear in performing the spot welding by overlapping a rear end part of a preceding metal plate on a forward end part of a succeeding metal plate before continuously performing the spot welding of metal plates of different width in a continuously welding equipment of the metal plate.

The spot welding is performed so that the formula of I0=II if 0≤L<M, or I0=(1+α)×II if M≤L is satisfied, where I0 is the welding current running in an electrode at a weld point located outermost in the plate width direction of an overlapping part, II is the welding current running in the electrode at a weld point located inside in the plate width direction of the overlapping part, and α is a coefficient, according to the relationship between the distance L between plate side ends at the overlapping part and the preset threshold M.