A sealing and pump-up device comprising: a sealing agent container body for containing a sealing agent, provided with an outflow section for letting the contained sealing agent flow out; a seal opening device for opening a seal member that seals the outflow section when the sealing agent container body is mounted to the seal opening device; a seal opening device retaining member (94A, 96A) for retaining the mounted state of the sealing agent container body to the seal opening device; a compressed air supply member that is connected to the seal opening device and supplies compressed air into the sealing agent container body sealed with the seal member; a fluid joint feed tube that is connected to the sealing agent container body and guides, into a pneumatic tire, sealing agent that has flowed out from the outflow section after the seal member is opened by the seal opening device and the compressed air supplied into the sealing agent container body by the compressed air supply member; characterized in that the device further comprises: a seal opening device fixing section (122, 128) for fixing the seal opening device to a casing body housing the compressed air supply member, wherein a fixing force of the seal opening device fixing section (122, 128) is weaker than a retaining force of the seal opening device retaining member (94A, 96A), wherein the seal opening device fixing section (122, 128) comprises: an indentation shaped female member provided to the seal opening device; and a male member that is inserted through an attachment hole formed in the casing body into the indentation shaped female member to couple to the female member and fix the seal opening device to the casing body. a sealing agent container body for containing a sealing agent, provided with an outflow section for letting the contained sealing agent flow out; a seal opening device for opening a seal member that seals the outflow section when the sealing agent container body is mounted to the seal opening device; a seal opening device retaining member (94A, 96A) for retaining the mounted state of the sealing agent container body to the seal opening device; a compressed air supply member that is connected to the seal opening device and supplies compressed air into the sealing agent container body sealed with the seal member; a fluid joint feed tube that is connected to the sealing agent container body and guides, into a pneumatic tire, sealing agent that has flowed out from the outflow section after the seal member is opened by the seal opening device and the compressed air supplied into the sealing agent container body by the compressed air supply member; characterized in that the device further comprises: a seal opening device fixing section (122, 128) for fixing the seal opening device to a casing body housing the compressed air supply member, wherein a fixing force of the seal opening device fixing section (122, 128) is weaker than a retaining force of the seal opening device retaining member (94A, 96A), wherein the seal opening device fixing section (122, 128) comprises: an indentation shaped female member provided to the seal opening device; and a male member that is inserted through an attachment hole formed in the casing body into the indentation shaped female member to couple to the female member and fix the seal opening device to the casing body. a seal opening device fixing section (122, 128) for fixing the seal opening device to a casing body housing the compressed air supply member, wherein a fixing force of the seal opening device fixing section (122, 128) is weaker than a retaining force of the seal opening device retaining member (94A, 96A), wherein the seal opening device fixing section (122, 128) comprises: an indentation shaped female member provided to the seal opening device; and a male member that is inserted through an attachment hole formed in the casing body into the indentation shaped female member to couple to the female member and fix the seal opening device to the casing body. an indentation shaped female member provided to the seal opening device; and a male member that is inserted through an attachment hole formed in the casing body into the indentation shaped female member to couple to the female member and fix the seal opening device to the casing body.