PURPOSE: To enable plural computer devices to use a printer in their set environment states at all times even when sharing the printer device.
CONSTITUTION: This printer sharing device has a data selective input means 1 which selectively inputs data sent from the respective computer devices 101-103 as plural data transmission sources, a data analyzing means 2 which extracts control data for control over the printer device 104 from the input data, an environment state storage means 3 which stores the environment states of the printer device 104 set with the control data extracted by the data analyzing means 2 by the data transmission sources which have sent out the control data, and an environment state setting means 4 which sets the environment state of the printer device 104 to the environment state for a newly switched data transmission source stored in the environment state storage means 3 when the data transmission source corresponding to the data received by the data selective input means 1 is switched.