Abstract: An automatic ground softening apparatus for crushing underground earth layer into pieces by blowing out compressed air from tips of air nozzle pipes driven deep into the ground at several positions at a time, is mounted on the load-carrying platform of a truck. The automatic ground softening apparatus includes a plurality of piston-cylinder assemblies mounted on the truck's load-carrying platform at different positions thereof. The air nozzle pipes each depend from the lower end of the piston rod of each of the piston-cylinder assemblies. Some or all of the piston-cylinder assemblies are operable through centralized control by operating an operating panel provided aside a driver's seat in the truck. The depth of driving of each air nozzle pipe driven by each piston-cylinder assembly into the ground and the pressure of compressed air jet from the tip nozzle of the air nozzle pipe into the earth can be set to desired values by operating the operating panel.