An observation apparatus according to one embodiment can include a timing generating unit (2) that generates a timing signal at a predetermined period. A sampling unit (3) can sample a current observation signal of a power supply current on the basis of the timing signal, and store sampled data in data storing unit (5). A data number adjusting unit (6) can adjust the number of data samples to a number that is a power of two. An arithmetic operating unit (4) can Fourier-transform the adjusted data to generate frequency spectrum results of the current observation signal. In addition, a failure inspection apparatus according to one embodiment analyzes the frequency spectrum of an integrated circuit under observation to determine a failure condition of the integrated circuit.