A target pressure detection device (1) includes a housing (10), a resilient membrane (12), and a pressure detection unit (14). The housing (10) forms a chamber (102) having an open end and the housing (10) forms a through hole (104). The resilient membrane (12) is mounted to the housing (10) to cover and close the open end of the housing (10) so as to set the chamber (102) in an air-tight condition. The pressure detection unit (14) is mounted to the through hole (104) and forms therein an accommodation compartment (140) that movably receives therein a floating element (142). The accommodation compartment (140) receives therein a sensor (144). The sensor (144) can effectively detect a movement of the floating element (142) and thus the precision of detection of the target can be improved through detecting change of airflow.