Many reports have discussed the swelling behavior of photoresists during development, as observed by the QCM method. Previously, we reported on the development of development analysis equipment based on the QCM method. In this paper, we report on a high-precision resist development analyzer also based on the QCM method. This equipment incorporates a high-precision developing solution temperature controller and features a high-precision air conditioning function for the measurement chamber. We also measured swelling behavior during development using a TBAH developer solution, which features larger molecules than TMAH, comparing these results with those obtained with TMAH. The results of this measurement indicate that the extent of resist swelling during development is less with TBAH developer solution than with TMAH developer solution. This result is consistent with results of a study by Itani et al. using high-speed AFM, suggesting the suitability of the measurement equipment used in our experiments.