An active matrix substrate facilitates correction of a pixel defect and a pixel defect correcting method. A laser target portion of a drain electrode extension portion is irradiated with laser light so as electrically disconnect a TFT from a subpixel electrode. Laser target portions are irradiated with laser light so as to melt an insulating layer, thereby establishing electrical connection between a drain electrode extension portion and a corrective connecting electrode and between a data signal line (13(m+1)) and the corrective connecting electrode. Laser target portions are irradiated with laser light, thereby establishing electrical connection between a drain electrode extension portion of a pixel P(n+1, m) and a corrective connecting electrode and between the data signal line (13(m+1)) and the corrective connecting electrode. Laser target portions are irradiated with laser light so as to separate part of the data signal line (13(m+1)) and use the separated part of the data signal line (13(m+1)) as a detour conductor.