A data recording apparatus for a vehicle equipped with an occupant protection device includes main and safing sensors for detecting acceleration of the vehicle, a temporary memory section for storing main and safing calculation values respectively calculated from detection results of the main and safing sensors, a control section for controlling the occupant protection device based on the main and safing calculation values and for determining whether a predetermined condition associated with the acceleration is satisfied, and a recording section for recording the main calculation value upon determination of the control section that the condition is satisfied. The recording section records the main calculation value for a first period before the determination and records the main calculation value for a second period after the determination. The recording section further records the safing calculation value for the second period.