Solid refrigerants exhibiting a caloric effect upon applying external stimuli may be an alternative to gaseous refrigerants. Herein, we report a new inorganic refrigerant, rubidium cyano-bridged manganese–iron–cobalt ternary metal assembly (cyano-RbMnFeCo). Cyano-RbMnFeCo shows a giant reversible barocaloric effect with extremely large reversible adiabatic temperature changes (|∆Tad,rev|) of 74 K (from 57 ℃ to −17 ℃) at 340 MPa, and 85 K (from 88 ℃ to 3 ℃) at 560 MPa. These are the largest |∆Tad,rev| values reported among all caloric effects. The reversible refrigerant capacity (RCrev) of 26000 J kg−1 and temperature window (Tspan,rev) of 142 K are also the largest values. Additionally, cyano-RbMnFeCo shows barocaloric effects even at low pressures, e.g., |∆Tad,rev| = 21 K at 90 MPa. Furthermore, direct measurement of the temperature change (∆Tobs) using a thermocouple shows ∆Tobs = +44 K by applying pressure, which is the largest practically measured temperature change among all caloric effect materials. The temperature increase and decrease upon pressure application and release is repeated over 100 cycles without any degradation of the ∆Tobs performance. This material series also possesses a high thermal conductivity value of 20.4 W m−1 K−1. The present barocaloric material may realize a high-efficiency solid refrigerant.