The signal collection method is a method that collects internal states indicated by signals in an electronic circuit device including a bus, the signal collection method including: storing the internal states with a fine resolution data storage by obtaining the internal states per a first period; per a second period, which is longer than the first period: obtaining a first data transfer amount, which is a data amount transferred by the bus, via a coarse resolution data storage; calculating a difference between a second data transfer amount and the first data transfer amount obtained in the obtaining, the second data transfer amount being calculated in advance and obtained from a cycle pattern generator; and determining whether the difference calculated in the calculating is within a predetermined range to stop storing in the storing when it is determined that the difference is not within the predetermined range.