Some aspects of recent improvements in temperature modulated calorimeter have been described. The contents are : (1) a low-frequency AC calorimeter with an improved resolution; delta C-p/C-p congruent to 0.010%, delta T similar to 7 mK; (2) an ultra-low frequency fully automated multifrequency AC calorimeter operated down to 0.5 mHz; and (3) a calorimeter with a capability of both AC-mode and relaxation-mode operations.