A hood lock apparatus configured to hold a hood of a vehicle in a closed state by locking a striker provided on the hood, the hood lock apparatus comprising: a base plate fixed to a vehicle body structural member of an engine compartment, the engine compartment being opened and closed by the hood, the base plate comprising a striker groove into which the striker enters in response to a closing operation of the hood; a latch rotatably supported on the base plate, the latch being configured to lock the striker entered into the striker groove so as not to exit from the striker groove; a locking plate rotatably supported on the base plate, the locking plate being configured to lock the latch, which locks the striker, so as not to rotate; a rattle lever rotatably supported on the base plate, the rattle lever being configured to hold the striker, which is locked by the latch, with the latch; and a rattle spring provided to extend between the base plate and the rattle lever, the rattle spring being configured to bias the rattle lever holding the striker with the latch towards the striker, wherein the rattle spring is disposed to straddle a first center line, the first center line passing through a rotational shaft of the rattle lever and extending in a direction which is at right angles to a direction in which the striker groove extends, wherein the latch comprises an engaging portion, wherein the rattle lever comprises an engaging portion, wherein the engaging portion of the latch and the engaging portion of the rattle lever being brought into engagement with each other so as to transmit a biasing force of the rattle spring from the rattle lever to the latch, and wherein in a state where the rattle lever holds the striker with the latch being locked by the locking plate, the engaging portion of the latch and the engaging portion of the rattle lever are spaced apart from each other. a base plate fixed to a vehicle body structural member of an engine compartment, the engine compartment being opened and closed by the hood, the base plate comprising a striker groove into which the striker enters in response to a closing operation of the hood; a latch rotatably supported on the base plate, the latch being configured to lock the striker entered into the striker groove so as not to exit from the striker groove; a locking plate rotatably supported on the base plate, the locking plate being configured to lock the latch, which locks the striker, so as not to rotate; a rattle lever rotatably supported on the base plate, the rattle lever being configured to hold the striker, which is locked by the latch, with the latch; and a rattle spring provided to extend between the base plate and the rattle lever, the rattle spring being configured to bias the rattle lever holding the striker with the latch towards the striker, wherein the rattle spring is disposed to straddle a first center line, the first center line passing through a rotational shaft of the rattle lever and extending in a direction which is at right angles to a direction in which the striker groove extends, wherein the latch comprises an engaging portion, wherein the rattle lever comprises an engaging portion, wherein the engaging portion of the latch and the engaging portion of the rattle lever being brought into engagement with each other so as to transmit a biasing force of the rattle spring from the rattle lever to the latch, and wherein in a state where the rattle lever holds the striker with the latch being locked by the locking plate, the engaging portion of the latch and the engaging portion of the rattle lever are spaced apart from each other.