Method of controlling a horizontal refrigerated display cabinet, said cabinet comprising at least one evaporator belonging to a steam compression refrigerant circuit and ventilation means suitable to generate a flow of air which circulates between the evaporator and the display compartment of said cabinet, said method being characterised by the fact that it keeps the evaporator constantly active with generation of cooling capacity and that it comprises the following operating steps: a) fixing a set temperature for the air temperature leaving the evaporator; b) measuring over time the temperature of the air flow leaving the evaporator; c) measuring over time the evaporation pressure of the refrigerant fluid at the evaporator; wherein the control of the cabinet is conducted by continuously regulating the evaporation pressure of the refrigerant fluid at the evaporator depending on the measured temperature values of the air so as to have the air flow leaving the evaporator at a temperature stable at the set value in regular functioning conditions of the cabinet, w herein the step b) of measuring the temperature of the air flow leaving the evaporator is performed by means of at least one temperature sensor installed in the path of the air flow downstream of the evaporator, the step c) of measuring the evaporation pressure of the refrigerant fluid at the evaporator being performed by means of a pressure transducer installed in the refrigeration circuit downstream of the evaporator, the evaporation pressure being regulated by means of a regulation valve installed in the refrigerant circuit downstream of the evaporator, said valve preferably being electronic, the regulation of the evaporation pressure being controlled by a programmable electronic control unit which receives the signals of the temperature sensor and pressure transducer in input and operates the pressure regulation valve depending on the measured pressure and temperature values, wherein in regular functioning conditions of the cabinet a step d) is performed of maintaining the temperature of the air leaving the evaporator at the set temperature by continuously regulating the evaporation pressure of the refrigerant fluid at the evaporator depending on the temperature measured values of the air, wherein in regular functioning conditions of the cabinet, having reached a situation of equilibrium between the heat removed from the cabinet and the heat provided to the cabinet by the surrounding environment - in the absence of external heat loads - the pressure is kept stable at an equilibrium value, wherein in regular functioning conditions of the cabinet, during the maintenance step d), in the presence of external heat loads which disturb the situation of equilibrium between the heat removed from the cabinet and the heat provided to the cabinet by the surrounding environment, the evaporation pressure is regulated by progressively reducing the pressure value as the temperature value of the air measured increases, and vice versa, depending on the air temperature measured, so as to restore a situation of equilibrium. a) fixing a set temperature for the air temperature leaving the evaporator; b) measuring over time the temperature of the air flow leaving the evaporator; c) measuring over time the evaporation pressure of the refrigerant fluid at the evaporator;