A dropout detection device, a disk reproduction apparatus, and a dropout detection method for detecting the occurrence of a dropout are provided. A low-pass filter outputs, as a signal LFENV, a low-frequency component of an envelope signal ENV generated by an envelope generation circuit, which represents an upper envelope of a first RF signal RF1 input from an RF amplifier unit. An adder adds a shift amount SH to the envelope signal ENV, and outputs a resultant signal as a shifted envelope signal SENV. A comparator outputs a dropout detection signal DET during a time period PT in which the signal LFENV is larger than the shifted envelope signal SENV. A detection control unit detects an amplitude ARF1 of the first RF signal RF1, and changes a frequency gain characteristic of the low-pass filter and the shift amount SH according to the magnitude of the detected amplitude AR1.