TWI768214B

To provide a technique which can inhibit a foreign matter from separating from a filter when starting to use the filter in filtering liquid with high viscosity.SOLUTION: A processing device 1 processes a filter 100 for filtering processing liquid with high viscosity. The processing device 1 comprises circulation piping 22 for circulating the processing liquid, liquid supply mechanism 23 for generating flow of the processing liquid in the circulation piping 22, and a fitting mechanism 25 and a foreign matter removing filter 24 which are interposed in a middle of a flow path of the circulation piping 22. The fitting mechanism 25 is detachably attached to the filter 100. In aging processing for the filter 100 using such processing device 1, the processing liquid is circulated to be used, which can reduce consumption of the processing liquid. Further, a foreign matter separating from the filter 100 can be removed by a device different from a device that is attached to the filter 100, which can eliminate the neces