The invention relates to an electromechanical brake booster with an electric motor and a helical gearing. The brake booster is used for coupling an auxiliary force via a driver into a piston rod. The invention proposes connecting a spindle of the helical gearing elastically via a spring element to the piston rod such that, in the event of rapid actuation of the brake, the helical gearing and a rotor of the electric motor do not have to be accelerated entirely muscle power. The muscle power required for actuating a brake is reduced as a result in the event of a rapid actuation of the brake.