Boiling heat transfer (BHT) is a promising technique for cooling the high heat flux emitted from next-generation electronic devices. However, critical heat flux (CHF) is a significant problem in BHT because it restricts the maximum performance of cooling devices using BHT. Nanofluid has been widely used to increase the CHF. In this study, the authors investigated the BHT of a compact cooling device at low pressure using a calcium carbonate nanofluid composed of partially soluble particles in water. The experimental result found that the CHF with the calcium carbonate nanofluid is 170 W/cm2 and does not deteriorate compared with nanofluid composed of insoluble nanoparticles. Furthermore, the total thermal resistance in the compact cooling device did not increase with the calcium carbonate nanofluid until 3000 min, while CHF was observed with the insoluble nanofluid at 1200 min.