An environmental sensitive electronic device package including a first substrate, a second substrate, an environmental sensitive electronic device, gas barrier structures, micro-structures, and a filler layer is provided. The second substrate is located above the first substrate. The environmental sensitive electronic device is located on the first substrate. The gas barrier structures may be located between the first substrate and the second substrate and surround the environmental sensitive electronic device. The gas barrier structures have a first height. The micro-structures may be located between the first substrate and the second substrate and have a second height. A ratio of the second height to the first height ranges from 1/250 to 1/100. The filler layer may be located between the first substrate and the second substrate and covers the gas barrier structures and the environmental sensitive electronic device. A manufacturing method of an environmental sensitive electronic device package is also provided.