SFR per radial parsec as a function of the disk radius in NGC 4565 obtained from the Hα data. The vertical dashed line indicates the mean radius of the truncation in the broadband optical data at 25.9  ±  0.4 kpc, and the shaded grey region is the uncertainty of the mean estimation. The radial bins are logarithmically spaced so the innermost bins are smaller than those in the outer parts of the disk. For the first time, we measure that NGC 4565 is forming stars at the truncation radius at a rate of 3.5 × 10⁻⁶  ±  5 × 10⁻⁶ M_⊙ yr⁻¹ pc⁻¹, or a total of 0.011  ±  0.002 M_⊙ yr⁻¹ within the bin.