In a container-cum-syringe (1) including a safety device (50), a coil spring (59) which biases the safety device (50) forward, first holding means (3) for causing the safety device (50) to be in a fastened state at a retreated position against the biasing of the coil spring (59), fastening releasing means (80) which is provided slidably along a radial direction of an axis (O) for releasing the fastened state of the safety device (50) by the first holding means (3) through a sliding movement, and locking means (70) for locking the fastened state of the safety device (50) by the first holding means (3) are provided. In this configuration, the safety device may be easily moved to a position for covering the injection needle. In addition, a malfunction of the safety device during an injecting operation may be reliably prevented.
