A breakdown measuring method and a breakdown measuring device are disclosed. The breakdown measuring method includes the following steps: capturing a plurality of process flows, each of the process flows includes at least one recipe step; analyzing a flow attribute corresponding to each of the process flows; capturing sensing data corresponding to the at least one recipe step; generating a local feature in a time interval corresponding to each of the process flows according to the corresponding flow attribute, the corresponding at least one recipe step and the corresponding sensing data; generating a trend distribution according to the local features of the process flows; determining whether to send an alarm information based on the trend distribution.