A substrate work system comprising: multiple substrate work devices (21-25,27,28) connected to each other via a network and configured to perform work on a substrate ; and a management device connected to the multiple substrate work devices (21-25,27,28) via the network and configured to manage the multiple substrate work devices (21-25,27,28), characterized by a first confirmation processing section (41A;15D) provided on at least one of the multiple substrate work devices (21-25,27,28) and configured to determine a cause for a communication error in a communication path in the network, the communication path connecting together at least two devices out of the multiple substrate work devices (21-25,27,28) and the management device , in response to an occurrence of a communication error in the network ; and a notification section (42;16C) configured to notify an occurrence of a communication error in the network and a result of confirmation by the first confirmation processing section (41A;15D). wherein the first confirmation processing section (41A;15D) determines a cause for the communication error in the communication path by making a confirmation communication between at least two devices out of the multiple substrate work devices (21-25,27,28) and the management device . wherein the substrate work system further comprises network configuration information (D1) necessary to specify a transmission destination for when data is transmitted to the multiple substrate work devices (21-25,27,28) via the network , and wherein the first confirmation processing section (41A;15D) transmits first confirmation data (D4) to at least one device out of the other substrate work devices (21-25,27,28) and the management device based on the network configuration information (D1) in response to an occurrence of a communication error in the network , and determines a cause for the communication error in the communication path in accordance with a reply to the first confirmation data (D4). multiple substrate work devices (21-25,27,28) connected to each other via a network and configured to perform work on a substrate ; and a management device connected to the multiple substrate work devices (21-25,27,28) via the network and configured to manage the multiple substrate work devices (21-25,27,28), characterized by a first confirmation processing section (41A;15D) provided on at least one of the multiple substrate work devices (21-25,27,28) and configured to determine a cause for a communication error in a communication path in the network, the communication path connecting together at least two devices out of the multiple substrate work devices (21-25,27,28) and the management device , in response to an occurrence of a communication error in the network ; and a notification section (42;16C) configured to notify an occurrence of a communication error in the network and a result of confirmation by the first confirmation processing section (41A;15D). wherein the first confirmation processing section (41A;15D) determines a cause for the communication error in the communication path by making a confirmation communication between at least two devices out of the multiple substrate work devices (21-25,27,28) and the management device . wherein the substrate work system further comprises network configuration information (D1) necessary to specify a transmission destination for when data is transmitted to the multiple substrate work devices (21-25,27,28) via the network , and wherein the first confirmation processing section (41A;15D) transmits first confirmation data (D4) to at least one device out of the other substrate work devices (21-25,27,28) and the management device based on the network configuration information (D1) in response to an occurrence of a communication error in the network , and determines a cause for the communication error in the communication path in accordance with a reply to the first confirmation data (D4). <EOS>