To provide a carved line drawing apparatus and a degradation state detection method for the carved line drawing tool, both capable of accurately detecting the abrasion (degradation) state of a cutter wheel.

The carved line drawing apparatus draws a carved line on a glass plate G by moving the cutter wheel 20 relatively to the glass plate G while the cutter wheel 20 is kept pressed against the glass plate G. The apparatus has a control device 30 equipped with an AE (acoustic emission) sensor 22 for detecting an AE wave emitted by the glass plate G and a cutter degradation state detection part 34 for detecting the abrasion (degradation) state of the cutter wheel 20. Based on the AE wave detected after drawing the carved line with the cutter wheel 20, the cutter degradation state detection part 34 detects the degradation state of the cutter wheel 20.