This cutter blade (15) for a mower (10A) is provided with: a blade base part (38); a cutting part (40) positioned further outward radially than the blade base part (38); a descending part (42) formed between the blade base part (38) and the cutting part (40); and a curved part (44) formed so as to curve upward from the cutting part (40). The descending part (42) and the curved part (44) comprise an intersection part (50) at which an end of the descending part (42) in the counter-rotating direction and a radially inner end of the curved part (44) intersect.