An electronic component mounting apparatus, comprising: a substrate transfer unit that transfers a substrate; an electronic component supply device (90, 90a) that supplies an electronic component; a head that includes a head main body and a head camera unit, wherein the head main body includes: a plurality of nozzles that hold electronic components and that are arranged in a row; a nozzle drive unit that drives the nozzles; and a head support body that supports the nozzles and the nozzle drive unit, wherein the head camera unit is fixed to the head support body and has a plurality of head cameras corresponding to the nozzles respectively for photographing electronic components held by the corresponding nozzles or electronic components to be held by the corresponding nozzles, wherein the head drives the nozzles to hold the electronic components, transfers the electronic components from the electronic component supply device (90, 90a) to the substrate and mounts the electronic components onto the substrate, a head moving mechanism that moves the head; and a control device that includes a camera control unit which processes images photographed by the head cameras and a head control unit which controls an operation of the head, wherein the camera control unit synthesizes the images photographed by the head cameras to generate an image with fields of the head cameras connected together, and the control device is configured to determine a process based on the image synthesized by the camera control unit, wherein the control device is configured to drive the head camera unit to photograph a range including a bad mark forming position of the substrate, the control device is configured to check whether a bad mark is present or not based on the synthesized image, and the bad mark forming position for arranging the bad mark thereon, the bad mark being a mark which, when a unit substrate is omitted from unit substrates for mounting electronic component, is formed on said unit substrate. a substrate transfer unit that transfers a substrate; an electronic component supply device (90, 90a) that supplies an electronic component; a head that includes a head main body and a head camera unit, wherein the head main body includes: a plurality of nozzles that hold electronic components and that are arranged in a row; a nozzle drive unit that drives the nozzles; and a head support body that supports the nozzles and the nozzle drive unit, wherein the head camera unit is fixed to the head support body and has a plurality of head cameras corresponding to the nozzles respectively for photographing electronic components held by the corresponding nozzles or electronic components to be held by the corresponding nozzles, wherein the head drives the nozzles to hold the electronic components, transfers the electronic components from the electronic component supply device (90, 90a) to the substrate and mounts the electronic components onto the substrate, wherein the head main body includes: a plurality of nozzles that hold electronic components and that are arranged in a row; a nozzle drive unit that drives the nozzles; and a head support body that supports the nozzles and the nozzle drive unit, a plurality of nozzles that hold electronic components and that are arranged in a row; a nozzle drive unit that drives the nozzles; and a head support body that supports the nozzles and the nozzle drive unit, wherein the head camera unit is fixed to the head support body and has a plurality of head cameras corresponding to the nozzles respectively for photographing electronic components held by the corresponding nozzles or electronic components to be held by the corresponding nozzles, wherein the head drives the nozzles to hold the electronic components, transfers the electronic components from the electronic component supply device (90, 90a) to the substrate and mounts the electronic components onto the substrate, a head moving mechanism that moves the head; and a control device that includes a camera control unit which processes images photographed by the head cameras and a head control unit which controls an operation of the head, wherein the camera control unit synthesizes the images photographed by the head cameras to generate an image with fields of the head cameras connected together, and the control device is configured to determine a process based on the image synthesized by the camera control unit, wherein the control device is configured to drive the head camera unit to photograph a range including a bad mark forming position of the substrate, the control device is configured to check whether a bad mark is present or not based on the synthesized image, and the bad mark forming position for arranging the bad mark thereon, the bad mark being a mark which, when a unit substrate is omitted from unit substrates for mounting electronic component, is formed on said unit substrate.