The paper introduces an Internet of Tings (IoT) Robot simulator. The aim of this simulator is to discuss issues for Context-Oriented Programming. The context-sensitive and live-adaptive are important features for next-generation systems such as IoT and Industrial 4.0. Context-Oriented Programming (COP) Languages give us adequate modularity to implement those features. IoT robot systems may cause problems related to the Internet (network connectivity and delay) and Things (physical phenomenon). These problems make it difficult to apply COP to IoT robot systems. The aim of this simulator is the clarification of COP problems on IoT robot systems that activate layers via the network. IoT robot systems are difficult to reproduce the previous situation since it depends on hardware and physical phenomena. To solve this problem, the simulator requires three features: (1) increase or decrease in the number of robots or obstacles, (2) representation of the network condition and delay, (3) logging and replay of context. We expect the mechanism contributes to imagine realistic issues of context-oriented software for constructing next generation robots. The paper presents a mechanism for this simulator system and shows the simulator finds some issues of context-oriented software.