A mobile radiation device comprising: a wheeled platform, wherein a radiation source that radiates radiation, a detector that detects the radiated radiation and outputs detected signals are installed to the wheeled platform; a grip bar that is gripped by the operator while said wheeled platform is moving; a driving means that drives said wheeled platform; a pressure sensor that detects the pressure added to said bar; an assist control means that drives said driving means according to the output from said pressure sensor; a velocity measurement means that measures the move velocity of said wheeled platform; a stop direction input means to input the direction for stopping said wheeled platform from the operator; a brake module that stops said wheeled platform that is moving; a velocity lowering control means that controls said driving means so as to add the braking force to lower the velocity of said wheeled platform that is moving on the horizontal pathway prior to turning said brake module operative by inputting the direction from the operator into said stop direction input means; and a brake control means that stops said wheeled platform by turning said brake module operative when the velocity of said wheeled platform decreases until the predetermined velocity by said velocity lowering control means; characterized in that: said braking control means turns said brake module operative when the velocity of said wheeled platform increases despite beginning of braking said wheeled platform by said velocity lowering control means. a wheeled platform, wherein a radiation source that radiates radiation, a detector that detects the radiated radiation and outputs detected signals are installed to the wheeled platform; a grip bar that is gripped by the operator while said wheeled platform is moving; a driving means that drives said wheeled platform; a pressure sensor that detects the pressure added to said bar; an assist control means that drives said driving means according to the output from said pressure sensor; a velocity measurement means that measures the move velocity of said wheeled platform; a stop direction input means to input the direction for stopping said wheeled platform from the operator; a brake module that stops said wheeled platform that is moving; a velocity lowering control means that controls said driving means so as to add the braking force to lower the velocity of said wheeled platform that is moving on the horizontal pathway prior to turning said brake module operative by inputting the direction from the operator into said stop direction input means; and a brake control means that stops said wheeled platform by turning said brake module operative when the velocity of said wheeled platform decreases until the predetermined velocity by said velocity lowering control means; characterized in that: said braking control means turns said brake module operative when the velocity of said wheeled platform increases despite beginning of braking said wheeled platform by said velocity lowering control means. said braking control means turns said brake module operative when the velocity of said wheeled platform increases despite beginning of braking said wheeled platform by said velocity lowering control means.