An eddy-current flaw detection device is provided that improves spatial resolution of flaw detection signals and signal reproducibility during redetection of flaws, and reduces interference signals with simple circuit construction. The eddy-current flaw detection device comprises a magnetic element group of which a specified number of magnetic elements are evenly spaced in each of at least two rows that are formed around the surface of a column shaped casing that is formed such that it can be inserted into a conductive pipe (not shown in the figures), with one row 11 to 18 being located at a position that differs from the other row 21 to 28 by 1/2 the even spacing in the row direction, and switching circuits for switching the magnetic elements in the respective row of the magnetic element group at time-division. The magnetic elements 11 to 18 of one row function as magnetic field excitation elements that excite a magnetic field by being switched at time-division, the magnetic elements 21 to 28 of the other r
